feat(deps): update dependency langchain-postgres to v0.0.18

Author: renovate-bot

requirements.txt

@@ -2,4 +2,4 @@ cloud-sql-python-connector[asyncpg]==1.20.0
 numpy==2.4.1; python_version >= "3.11"
 numpy==2.2.6; python_version == "3.10"
 langgraph==1.0.10
-langchain-postgres==0.0.17
+langchain-postgres==0.0.18